Footwear with improved upper

ABSTRACT

Flexible shoe extending between rear and front ends, between lateral and medial sides, and between the sole assembly and an upper end of an upper. The upper includes an outer shell including an inner and outer layers, the latter having a foot insertion opening with rear and front divisions, the latter extending between lateral and medial edges. A device tightens the upper by bringing the lateral edge toward the medial edger. The inner layer extends opposite the outer layer and in the area of the front division of the foot insertion opening, between the lateral and medial edges. The inner layer is liquid-impermeable and flexible. When the lateral and medial edges of the outer layer are brought toward one another, the distance between the lateral and medial edges is shorter than the portion of the inner layer in the area of the front division or the foot insertion opening.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon French Patent Application No. FR17/00405, filed Apr. 12, 2017, the disclosure of which is herebyincorporated by reference thereto in its entirely, and the priority ofwhich is claimed under 35 U.S.C. § 119.

BACKGROUND 1. Field of the Invention

The invention relates to a walking or sports article of footwear, suchas a shoe, having a liquid-impermeable upper. This shoe can be used infields such as walking, running on flat or mountainous terrain,skateboarding, ball sports, cross-country or telemark skiing,snowboarding, snowshoeing, or others.

2. Background Information

Depending upon the intended uses, a shoe must have a certain flexibilityand a good damping capability. Flexibility must be understood as anability to follow certain deformations of the foot of a user. This isintended, for example, to enable good foot rolling movement whenwalking. Damping is intended to reduce or even prevent fatigue orinjuries that may result from supports or impacts on the ground, or fromvarious forces.

The shoe must also fulfill other functions such as preserving footcomfort, for example by preventing intrusion of water, that is to say,by ensuring that the foot remains dry or is subject to the lowestpossible moisture rate.

To this end, it is known to make a flexible shoe such as shown withreference to FIGS. 1-3, which are part of a set that is described indetail below. According to these drawing figures, a shoe 1 comprises asole assembly 2 and an upper 3, the upper comprising an outer shell 4,which itself comprises an outer layer 5 and an inner layer 6.

For example, the outer layer 5 has mechanical strength properties, suchas resistance to wear and tear or resistance to the tightening forcesexerted by a tightening device provided with a lace 7. The outer layer 5has a root insertion opening 8 divided into a rear division 9, in whicha portion of the ankle or of the lower leg of the user is received, anda front division 10 located above the foot, or at the front of the lowerleg and above the foot, after putting on the shoe. The front division 10makes it possible to easily increase or decrease the surface of theopening 8, and therefore to easily put on the shoe, tighten the upper,and take off the shoe.

The inner layer 6 has other properties, such as liquid impermeability,in order to carry out the sealing function. Usually, the inner layer 6extends opposite the outer layer 5, thereby rendering most of the upper3 impermeable to liquids. In order for the upper to be impermeable inits entirety, the front division 10 of the foot insertion opening 8 mustbe liquid-tight. The division 10 is generally hidden by an outer flap11, an inner flap 12, and an insert 13 positioned between the flaps. Theinner flap 12, impermeable to liquid, is connected to the inner layer 6by means comprising one or more seams 14 and one or more strips 15.These strips are attached by gluing in the area of the seams 14, toprevent water from seeping therethrough.

The above construction renders the upper 3 impermeable to liquid, suchas water, and therefore keeps the foot dry. The absence of water in theshoe significantly limits the occurrence of injuries. Consequently, ashoe according to the prior art is generally satisfactory for the user.However, certain disadvantages have nevertheless been observed.

First, a liquid-impermeable shoe according to the prior art sometimesoffers insufficient comfort in the area of the front division of thefoot insertion opening, particularly when practicing a sporting orintense activity. When the upper is tightened, substantial pressure canbe exerted locally on the top of the foot, in correlation with theaction of the lace. It is notably in the area of the seams and extrathicknesses created by the strips that excessive pressure can occur, asthe upper is more rigid in these areas of extra thickness. As a result,injuries may occur.

Another disadvantage is related to the relative complexity of thestructure of a shoe having a liquid-impermeable upper. Because of thenumber of parts involved, the manufacture of such a shoe is quitelengthy and expensive. For example, as understood with reference to FIG.3, in a schematic representation, it is quite difficult to affix theconstituent elements of the upper 3 to one another. This upper ismanufactured with a generally V-shaped preform, the opening angle α ofwhich is between 20 and 40 degrees. In fact, the elements are assembledflat, with the exception of the inner flap 12, which must therefore bedeformed to enable its edges to be positioned for assembly. Thisoperation is difficult and time-consuming. In addition, it is necessaryto add the strips 15 (see FIG. 2), as mentioned above, which furtherincreases the time required for the manufacture.

SUMMARY

In view of the preceding, the invention provides an improved shoe. Inparticular, the invention increases comfort in a shoe having aliquid-impermeable upper. The invention also optimizes the manufactureof the shoe, making it faster and more economical, compared to a shoeaccording to the prior art.

To this end, the invention provides a flexible shoe comprising a soleassembly and an upper, the shoe extending lengthwise from a rear end toa front end, widthwise between a lateral side and a medial side, andheightwise from the sole assembly to an upper end, the upper comprisingan outer shell, the outer shell comprising an outer layer and an innerlayer, the outer layer having a foot insertion opening, the footinsertion opening having a rear division and a front division, the frontdivision extending in the direction of the shoe width, between a lateraledge and a medial edge, the shoe further comprising a device fortightening the upper by bringing the lateral edge and medial edge closerto one another.

A shoe according to the invention includes the following features:

-   -   the inner layer extends opposite the outer layer and in the area        of the front division of the foot insertion opening, between the        lateral edge and the medial edge;    -   the inner layer is impermeable to liquid;    -   the inner layer is flexible; and    -   in the direction of the shoe width, when the lateral edge and        medial edge of the outer layer are brought closer to one        another, the distance between the lateral edge and the medial        edge is shorter than the portion of the inner layer extending in        the area of the front division of the foot insertion opening.

The structure of a shoe according to the invention is such that theinner layer of the outer shell extends continuously from the lateralside to the medial side, passing via the front division of the footinsertion opening. As a corollary, the inner layer comes into contactwith the foot of the user in a more homogeneous, or uniform, manner.Also, the mechanical properties of the outer shell are more uniform fromthe lateral side to the medial side, in particular with respect tobending or flexing. This means for example that the hard spots observedin the area of the strips of a shoe according to the prior art are notfound on a shoe according to the invention: the outer shell is morehomogeneous with respect to its flexibility. As a result, comfort isbetter distributed; no hard spot is noticeable. It follows that theforces exerted by the upper are more evenly distributed on the foot,especially in the region of the front division of the foot insertionopening. In other words, the distribution of the tightening forces ismore homogeneous or uniform on the top of the foot, in the area of theinstep, or even simultaneously in the area of the instep and in the areaof the flexion fold, that is, the flexion crease. A resulting advantageis greater foot comfort in the shoe.

Another consequence of the structure of a shoe according to theinvention is a simpler construction compared to a shoe according to theprior art. The invention allows for a reduction in the number of partsrequired to make the shoe. As described below, the invention alsofacilitates the shoe manufacturing process, requiring a reduced numberof operations and further simplifying such operations. It follows inparticular that the parts forming the structure of the shoe are moreeasily assembled. The resulting advantages include shorter manufacturingtime, reduced manufacturing cost, and greater manufacturing homogeneity,or uniformity. This latter feature means that the differences in fittingvolume between two shoes of the same size are reduced, compared to thedifferences that are observed on shoes according to the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will be betterunderstood from the description that follows, with reference to theannexed drawing figures illustrating prior art and non-limitingembodiments, in which:

FIG. 1 is a perspective view of a shoe according to the prior art;

FIG. 2 is a transverse cross section of the shoe along the line 11-11 ofFIG. 3;

FIG. 3 is a flat partial schematic view of a preform of the outer shellof the shoe of FIG. 1;

FIG. 4 is a cross section of the preform along the line IV-IV of FIG. 3;

FIG. 5 is a perspective view of a shoe according to a first embodimentof the invention;

FIG. 6 is a transverse cross section of the shoe along the line VI-VI ofFIG. 5, in a case in which the device for tightening the upper exerts atightening action;

FIG. 7 is a view similar to that of FIG. 6, in a case in which thedevice for tightening the upper does not exert a tightening action;

FIG. 8 is a flat partial schematic view of a preform of the inner shellof the shoe of FIG. 5;

FIG. 9 is a view similar to that of FIG. 8, according to a secondembodiment of the invention, and

FIG. 10 is a view similar to that of FIG. 8, according to a thirdembodiment of the invention.

DETAILED DESCRIPTION

The first embodiment described below relates, for example, to a flexibleshoe for walking on firm ground or in snow. However, the invention isapplicable to other fields, such as those mentioned above.

The first embodiment is described with reference to FIGS. 5 to 8.

As shown in FIG. 5, a walking shoe 21 is provided to receive the foot ofthe user. Conventionally, the shoe 21 comprises an outer sole assembly22 and an upper 23 affixed to the sole assembly. The shoe extendslengthwise, along a longitudinal direction L, from a rear end 24 to afront end 25, and widthwise, along a transverse direction W, between alateral side 26 and a medial side 27.

As shown, the upper 23 comprises a lower portion 30, provided tosurround the foot, and has no upper portion. However, an upper mayalternatively be provided to comprise both a lower portion and an upperportion, the latter being provided to surround the ankle and possibly aportion of the lower leg of the wearer.

According to the first embodiment being described, the shoe 21 extendsheightwise from the bottom surface of the outer sole assembly 22 to anupper end 32, that is to say, up to the free end of the upper 23.

The shoe 22 is structured to allow smooth rolling movement of the footduring walking (for example, the shoe flexes at a flexion crease, suchas at the metatarsophalangeal joint, as the heel is raised and loweredin relation to the toe), transmissions of sensory information, andimpulses for supports or jump landings. This is why the outer soleassembly 22 and the upper 23 are relatively flexible.

As can be seen in FIGS. 6 and 7, the upper 23 comprises an outer shell33 that includes an outer layer 34 and an inner layer 35. Each layer 34,35, shown schematically, comprises the number of components necessary tocarry out the desired function(s). This is described in more detailbelow.

As can be understood with reference to FIGS. 5 to 8, the outer layer 34has a foot insertion opening 36 that has a rear division 37 and a frontdivision 38, the front division extending in the direction of the shoewidth, that is to say, along the transverse direction W, between alateral edge 41 and a medial edge 42. The rear 37 and front 38 divisionsare coextensive to facilitate the passage of the foot when putting on ortaking off the shoe.

The shoe 21 further includes a device 43 for tightening the upper 23 bybringing the lateral edge 41 and medial edge 42 closer to one another.In a non-limiting manner, the upper tightening device 43 includes atleast one lateral keeper 44, at least one medial keeper 45, and at leastone linkage 46 running through the keepers 44, 45. The keepers areexemplary and can take any of a plurality of forms that include holes oreyelets through which a linkage or lace extends and structures aroundwhich the linkage or lace slides.

According to the invention, the inner layer 35 extends opposite theouter layer 34 (and in the illustrated embodiment they are in engagementwith each other) and, in the area of the front division 38 of the footinsertion opening 36, between the lateral edge 41 and the medial edge42. The inner layer 35 is impermeable to liquid. The inner layer 35 isflexible. And, in the direction of the shoe width, when the lateral edge41 of the front division 38 and the medial edge 42 of the front division38 of the outer layer 34 are brought closer to one another, the distancebetween the lateral edge 41 and medial edge 42 is shorter than theportion of the inner layer 35 extending in the area of the frontdivision 38 of the foot insertion opening 36. Finally, a shoe accordingto the invention is simpler to manufacture and more comfortable, as hasbeen explained above, than a shoe according to the prior art.

Still in the context of the invention, specific properties can beconferred on the inner layer 35, as described below.

According to a variation that is part of the first embodiment, the innerlayer 35 is inextensible, which, for example, makes it easy to cut andthereby facilitates the manufacture. In another variation of the firstembodiment the inner layer 35 is extensible, which can help the outershell 4 to adapt even better to the shape of the foot. These areselective details that in no way change the context of the invention.

Still for the first embodiment, and in a non-limiting manner, the innerlayer 35 of the outer shell 33 includes a membrane and a lining. Theseelements are not shown in detail in the drawing figures as they are wellknown to one having ordinary skill in the art. For example, the membraneis impermeable to liquid and permeable to gas. In other words, themembrane is breathable-waterproof, that is to say, it allows a gas, suchas water vapor, to pass therethrough, but blocks the passage of aliquid, such as water. This improves the comfort of the foot. Themembrane is made of polymeric materials such as polyolefin,polyethylene-propylene copolymer, polyethylene, terephthalate,polycaprolactone, polyvinyl fluoride, polybutylene terephthalate,polyester copolymer, polytetrafluoroethylene, or the like. For example,the membrane comprises a porous polytetrafluoroethylene sheet and apolyurethane layer. Further, and again without limitation, the thicknessof the membrane is between 5.0 and 250 micrometers, for example. Thisreduced thickness contributes to making the inner layer 35 of the outershell 33 flexible and light.

As shown more specifically to FIGS. 6 and 7, the outer shell 33 of theupper 23 includes a flexible flap 47 extending in the area of the frontdivision 38 of the foot insertion opening 36. In fact, the flap 47 isarranged between the linkage of the tightening device 43 and the innerlayer 35 of the outer shell 33. The flap preserves the inner layer 35against a possible shearing effect that may be exerted by the linkage,particularly in the case of very intense use of the shoe. As describedbelow, the flap 47 may carry out other functions.

An insert 48 is fitted between the inner layer 35 of the outer shell 33and the flexible flap 47. This insert is for example made of a flexiblesynthetic foam block, which can be polyurethane foam, polyethylene vinylacetate foam, or any suitable material known to one of ordinary skill inthe art. Because it contributes to the distribution of stresses relatedto the action of the linkage 46 during tightening, the insert 48 furtherimproves comfort during use of the shoe. The flap 47, in collaborationwith the inner layer 35, thus carries out a function of maintaining theinsert 48 in the area of the front division.

With reference more particularly to FIG. 6, when the lateral edge 41 andmedial edge 42 of the front division 38 of the foot insertion opening 36are brought closer to one another, for example by the action of thetightening device 43, the inner layer 35 forms a lateral fold 51 in thearea of the lateral edge 41. Similarly, when the lateral edge 41 andmedial edge 42 of the front division 38 of the foot insertion openingare brought closer to one another, the inner layer 35 forms a medialfold 52 in the area of the medial edge 42. It is thus understood thatthe central portion 53 of the inner layer 35, located in the area of thefront division 38 of the foot insertion opening 36, becomes deformed atthe same time as the lateral 41 and medial 42 edges are brought closerto one another. The central portion is actually capable of becomingdeformed by folding in the manner of a bellows. In fact, the inner layer35 is folded in the area of its central portion 53 when the upper istightened. In this case, the fitting volume is reduced.

Conversely, with reference to FIG. 7, the inner layer 35 is unfolded inthe area of its central portion 53 when the upper is loosened. In thiscase, the fitting volume is substantial. The tightening device 43 doesnot exert its tightening action, and the lateral edge 41 and medial edge42 of the front division 38 of the foot insertion opening 36 are spacedapart.

As can also be seen in both FIG. 6 and in FIG. 7, the shoe 21 includes alasting board 54. In a non-limitng manner, this lasting board is affixedto the upper 23 by a seam 55, in this case a Strobel-type seam. It canbe said more precisely that the lasting board 54 is affixed to the outershell 33 by the seam 55. The seam is not described in detail here as itis well known to one of ordinary skill in the art. Manufacturing theshoe 21 with a sewn lasting board, as opposed to an adhesively affixedlasting board, makes it possible to obtain a fitting volume that iscloser to the shape of a foot. Advantageously, it follows that the shoeoffers greater comfort, compared to what it would be an adhered lastingboard.

As shown in FIG. 8, the inner layer 35 of the outer shell 33 is made ina single piece. This means that the inner layer extends over the entireupper 23. This does not prevent the inner layer 35 from including aplurality of thicknesses, as mentioned above, including a membrane and alining. The inner layer 35 is generally V-shaped, having an openingangle β between 45 and 90 degrees. The inner layer 35 is assembled withthe outer layer 34, which has the same overall appearance as the innerlayer 35. However, the outer layer 34 has a notch 56, shown as a dottedline between the lateral 41 and medial 42 edges, for receiving theflexible flap 47, not shown in FIG. 8. Finally, the upper 23 is madefrom a generally V-shaped preform, having an opening angle β between 45and 90 degrees. According to the invention, the elements forming theouter shell 33 are assembled flat. The shoe manufacturing process isthus simplified.

Other embodiments of the invention are described below with reference toFIGS. 9 and 10. For reasons of convenience, the elements shared with thefirst embodiment are designated by the same reference numerals.

According to the second embodiment, as can be seen in FIG. 9, the innerlayer 35 of the outer shell 33 is an assembly of two portions 61, 62.This configuration makes it possible to optimize the cutting of materialfor the manufacture of the shoe. More specifically, the scraps ofmaterial generated by the cutting of plies are smaller. Given that theprice per unit area is very high in the case of a membrane impermeableto water and permeable to gas, the resulting saving is substantial.

Still for the second embodiment, the portions 61, 62 are assembled withone another to assume the general appearance of the inner layer 35. Theassembly is done via a combination of stitching and adhesively affixedstrips, which are located in the area of the lateral side 26 and medialside 27 of the shoe 21. This location of seams and strips is outside ofthe zones of the upper that are subject to bending or to the action ofthe tightening device. As a result, foot comfort is preserved.

In the same spirit, according to the third embodiment, as can be seen inFIG. 10, the inner layer 35 of the outer shell 33 is an assembly ofthree portions 63, 64, 65. Here again, the configuration allowsoptimizing the cutting of material for the manufacture of the shoe, andthe resulting saving is substantial.

Again, the portions 63, 64, 65 are assembled with one another to assumethe general appearance of the inner layer 35. The assembly is done via acombination of stitching and adhesively affixed strips, which arelocated in the area of the lateral side 26, medial side 27, and rear end24 of the shoe 21. This location of seams and strips is outside of thezones of the upper that are subject to bending or to the action of thetightening device. As a result, foot comfort is preserved.

In any case, the invention is made from materials and according toimplementation techniques known to one of ordinary skill in the art.

The invention is not limited to the embodiments described above, andincludes all technical equivalents that fall within the scope of theclaims that follow.

For example, one can provide a configuration for which the outer layer34 and inner layer 35 of the outer shell 33 are affixed to one anotherby glue dots 39, that is, by spots of glue spaced apart within theinterface between the inner and outer layers of the outer shell. Gluedots 39 are shown in FIGS. 6 and 7, but are optional in the previouslydescribed embodiment. The glue dots improve the ability of the outershell 33 to grip the foot evenly, while preserving its ability to blockthe intrusion of water and to allow gas to pass therethrough.

Generally speaking, the flexible flap 47 extends over an area between80% and 100% of the front division 38 of the foot insertion opening 36.This optimizes the function of protecting the top of the foot. Theflexible flap 47 also sometimes extends over an area greater than 100%of the front division 38 to obtain protection against obstacles, such aslow hanging branches, in the area of the flexion crease.

Further, at least because the invention is disclosed herein in a mannerthat enables one to make and use it by virtue of the disclosure ofparticular exemplary embodiments, such as for simplicity or efficiency,for example, the invention can be practiced in the absence of anyadditional element or additional structure that is not specificallydisclosed herein.

1. Flexible shoe comprising: a sole assembly; an upper extendingupwardly from the sole assembly; the shoe extending: lengthwise from arear end to a front end; widthwise between a lateral side and a medialside; and heightwise from the sole assembly to an upper end; the uppercomprising: an outer shell comprising: an inner layer; an outer layercomprising a foot insertion opening that includes a rear division and afront division; the front division extending widthwise between a lateraledge and a medial edge of the foot-insertion opening; anupper-tightening-device configured to bring the lateral edge and medialedge closer to one another; the inner layer extending opposite the outerlayer and in the area of the front division of the foot insertionopening, between, the lateral edge and the medial edge; the inner layerbeing a liquid-impermeable layer; the inner layer being a flexiblelayer; and a distance between the lateral edge and medial edge isshorter than the portion of the inner layer extending in the area of thefront division of the foot insertion opening when the lateral edge andmedial edge of the outer layer are brought closer to one another by theupper-tightening-device.
 2. Shoe according to claim 1, wherein: theinner layer of the outer shell comprises a membrane and a lining. 3.Shoe according to claim 2, wherein: the membrane is impermeable toliquid and permeable to gas.
 4. Shoe according to claim 2, wherein: thethickness of the membrane is between 5.0 and 250 micrometers.
 5. Shoeaccording to claim 1, wherein: the outer shell of the upper comprises aflexible flap extending in the area of the front division of the footinsertion opening.
 6. Shoe according to claim 5, wherein: an insert isfitted between the inner layer of the outer shell and the flexible flap.7. Shoe according to claim 1, wherein: when the lateral edge and medialedge of the front division are brought closer to one another, the innerlayer forms a fold in the area of the lateral edge.
 8. Shoe according toclaim 1, wherein: when the lateral edge and medial edge of the frontdivision are brought closer to one another, the inner layer forms a foldin the area of the medial edge.
 9. Shoe according to claim 1, furthercomprising: a lasting board.
 10. Shoe according to claim 1, wherein: thetightening device comprises at least one lateral keeper, at least onemedial keeper, and at least one linkage extending through the keepers.11. Shoe according to claim 1, wherein: the inner layer of the outershell is made in a single piece.
 12. Shoe according to claim 1, wherein:the inner layer of the outer shell is an assembly of two portions. 13.Shoe according to claim 1, wherein: the inner layer of the outer shellis an assembly of three portions.
 14. Shoe according to claim 1,wherein: the outer layer and inner layer of the outer shell are affixedto one another by glue dots.
 15. Shoe according to claim 1, wherein:each of the outer sole and the upper has a flexible structure allowingthe shoe to flex during use at a flexion crease of the shoe.